The author presents clever devices to scale down everything from time lines (the history of Earth compressed into one year), to quantities (all the wealth in the world divided into one hundred coins), to size differences (the planets shown as different types of balls).

If... -- Our galaxy -- The planets -- History of Earth -- Life on Earth -- Events of the last 3000 years -- Inventions through time -- Inventions of the last 1000 years -- The continents -- Water -- Species of living things -- Money -- Energy -- Life expectancy -- Population -- Food -- Your life -- A note for parents and teachers.